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CVE-2026-96808

CVE-2026-96808

This page contains facts from public vulnerability sources. Check the original advisory before updating.

In Flatpak before 1.18.1, the revokefs writer, used by the flatpak-system-helper to receive repository data from unprivileged callers, validated file paths by rejecting literal .. components but did not prevent symlink traversal. A malicious local user in an active local session could obtain two revokefs sessions via the system helper, create a symlink in one session pointing into the other session's directory, and retain a file descriptor through that symlink. This allowed the attacker to modify files belonging to a different revokefs session after they had been validated and imported by the system helper. In particular, an attacker could use this to tamper with ostree commit objects in the system repository after they passed signature verification, enabling root-controlled file writes to attacker-chosen paths and local root privilege escalation.

CVSS 7.4 · High · EPSS 0.1% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • flatpak

    Versions
    • ≥ 0, < 1.18.1: Affected (semver)

    Update to 1.18.1

  • flatpak Debian:12

    Versions
    • 1.14.10-1
    • 1.14.10-1~deb12u1
    • 1.14.10-1~deb12u2
    • 1.14.4-1
    • 1.14.4-1+deb12u1
    • 1.14.4-1+deb12u1~bpo11+1
    • 1.14.4-2
    • 1.14.5-1
    • 1.14.6-1
    • 1.14.6-1~deb13u1
    • 1.14.8-1
    • 1.14.8-1~deb12u1
    • 1.15.0-1
    • 1.15.0-2
    • 1.15.1-1
    • 1.15.10-1
    • 1.15.12-1
    • 1.15.2-1
    • 1.15.3-1
    • 1.15.4-1
    • 1.15.6-1
    • 1.15.7-1
    • 1.15.8-1
    • 1.15.9-1
    • 1.15.91-1
    • 1.16.0-1
    • 1.16.0-2
    • 1.16.0-2~bpo12+1
    • 1.16.1-1
    • 1.16.1-1~bpo12+1
    • 1.16.1-2
    • 1.16.1-3
    • 1.16.2-1
    • 1.16.2-1~deb13u1
    • 1.16.3-1
    • 1.16.3-1~deb13u1
    • 1.16.4-1
    • 1.16.4-2
    • 1.16.5-1
    • 1.16.6-1
    • 1.16.6-1~deb13u1
    • 1.16.6-1~deb13u1~bpo12+1
    • 1.16.6-1~deb13u2
    • 1.17.2-1
    • 1.17.3-1
    • 1.17.3-2
    • 1.17.6-1
    • 1.18.0-1
    • 1.18.1-1
    • 1.18.2-1
    • 1.18.3-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • flatpak Debian:13

    Versions
    • 1.16.1-1
    • 1.16.1-2
    • 1.16.1-3
    • 1.16.2-1
    • 1.16.2-1~deb13u1
    • 1.16.3-1
    • 1.16.3-1~deb13u1
    • 1.16.4-1
    • 1.16.4-2
    • 1.16.5-1
    • 1.16.6-1~deb13u1
    • 1.16.6-1~deb13u1~bpo12+1
    Affected ranges
    • ECOSYSTEM: < 1.16.6-1~deb13u2

    Update to 1.16.6-1~deb13u2

  • flatpak Debian:14

    Versions
    • 1.16.1-1
    • 1.16.1-2
    • 1.16.1-3
    • 1.16.2-1
    • 1.16.2-1~deb13u1
    • 1.16.3-1
    • 1.16.3-1~deb13u1
    • 1.16.4-1
    • 1.16.4-2
    • 1.16.5-1
    • 1.16.6-1
    • 1.16.6-1~deb13u1
    • 1.16.6-1~deb13u1~bpo12+1
    • 1.16.6-1~deb13u2
    • 1.17.2-1
    • 1.17.3-1
    • 1.17.3-2
    • 1.17.6-1
    • 1.18.0-1
    Affected ranges
    • ECOSYSTEM: < 1.18.1-1

    Update to 1.18.1-1

  • flatpak Ubuntu:Pro:18.04:LTS

    Versions
    • 0.8.7-5
    • 0.10.0-1
    • 0.10.0-2
    • 0.10.1-1
    • 0.10.2-1
    • 0.10.2.1-1
    • 0.10.2.1-2
    • 0.10.3-1
    • 0.11.1-0ubuntu1
    • 0.11.3-2
    • 0.11.3-3
    • 0.11.7-0ubuntu0.1
    • 1.0.1-0ubuntu0.1
    • 1.0.6-0ubuntu0.1
    • 1.0.7-0ubuntu0.18.04.1
    • 1.0.8-0ubuntu0.18.04.1
    • 1.0.9-0ubuntu0.1
    • 1.0.9-0ubuntu0.2
    • 1.0.9-0ubuntu0.3
    • 1.0.9-0ubuntu0.4
    • 1.0.9-0ubuntu0.4+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • flatpak Ubuntu:Pro:20.04:LTS

    Versions
    • 1.4.3-1
    • 1.6.0-1
    • 1.6.1-1
    • 1.6.2-1
    • 1.6.3-1
    • 1.6.5-0ubuntu0.1
    • 1.6.5-0ubuntu0.2
    • 1.6.5-0ubuntu0.3
    • 1.6.5-0ubuntu0.4
    • 1.6.5-0ubuntu0.5
    • 1.6.5-0ubuntu0.5+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • flatpak Ubuntu:Pro:22.04:LTS

    Versions
    • 1.10.2-3
    • 1.12.2-1
    • 1.12.2-2
    • 1.12.3-1
    • 1.12.4-1
    • 1.12.5-1
    • 1.12.6-1
    • 1.12.7-1
    • 1.12.7-1ubuntu0.1
    • 1.12.7-1ubuntu0.1+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • flatpak Ubuntu:Pro:24.04:LTS

    Versions
    • 1.14.4-2
    • 1.14.5-1
    • 1.14.5-1build1
    • 1.14.5-1build4
    • 1.14.5-1build5
    • 1.14.5-1build6
    • 1.14.6-1
    • 1.14.6-1ubuntu0.1
    • 1.14.6-1ubuntu0.1+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • flatpak Ubuntu:26.04:LTS

    Versions
    • 1.16.1-2ubuntu1
    • 1.16.1-3ubuntu1
    • 1.16.2-1
    • 1.16.3-1
    • 1.16.3-1build1
    • 1.16.4-1
    • 1.16.4-2
    • 1.16.6-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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